The Log-normal Distribution

Abstract

The purpose of this brief note is to share some very simple observations concerning the log-normal distribution. I have found this distribution useful chiefly for two reasons. First, it describes a non-negative random variable, such as the time between two events, or the concentration of a pollutant. Second, the log-normal distribution can have any coefficient of variation between zero and infinity. This is not true of other positive distributions, such as 'the gamma and beta distributions.